The Footprint of Gmail: How Much Energy Would Deleting Email Save?

Like so many others, this TreeHugger made the switch to Gmail a while back, and has never looked back. He immediately started making use of its massive storage capabilities, and stopped deleting anything but the most obviously pointless emails. His email inbox is rapidly approaching the 11,000 messages mark. Being the technologically-challenged individual that he is, it took him some time to realise that there might be consequences to these actions – namely data retained means storage space used, and storage space used means energy consumed. The more tech savvy reader is probably shaking her head right now, amazed at how it can take this long to realise such things, but the fact remains that many of us still see digital files as existing in some kind of limbo – if they are not using up paper, or taking up storage space in our filing cabinets, what kind of impact can they have? As Lloyd pointed out in his post on the paperless home, moving from paper to digital storage is leading to major increases in energy consumption, and Google itself acknowledges it is "as much of an energy glutton as heavy industry". But just how much energy are we using up by not keeping our Gmail inboxes in order? This question lead to some interesting discussion among TreeHugger staff, with our resident computer-guru Mark Ontkush informing us that it is almost impossible to get accurate numbers. Apparently it used to be the accepted wisdom that 2MB of data required about a lb of coal to store annually, but this figure was based on a study from 1999 which has supposedly since disappeared from the internet (no mean feat, as Mark points out!). Whether this study was accurate at the time or not, the numbers stuck around in popular discourse. Apparently this was recalculated to somewhere between 10 and 20MB per lb of coal in 2003, but even those figures are likely to be way out of date by now. Whatever the exact energy use per unit of storage is, we do know that the internet uses somewhere around 3% of US electricity consumption – a pretty sizeable figure.

Mike also waded into the debate, pointing out that there are so many variables – from how much data is stored for how long and where, to how often it is accessed, from where, on which machines. Add to that the question of what the grid mix is for the locations in question, and the fact that from one request to the next, things can be routed to different places or gotten from RAM or HDD, at different data centers. Ultimately is seems that the only thing we can say in the end is this - less data equals less power by some amount.

Mike concluded by suggesting that the real question is opportunity cost: how much effort would we put into reducing emails, and would that effort be better used elsewhere? We’d love to hear our readers thoughts on this – meanwhile this author will be at least trying to get his inbox down under the 10,000 messages mark, though he’s going to try not to delete the discussion thread that started all this.

Like so many others, this TreeHugger made the switch to Gmail a while back, and has never looked back. He immediately started making use of its massive storage capabilities, and stopped deleting anything but the most obviously pointless emails. His